Composition paper or pulp board and method of making the same



Patented Nov. 8, 1927.

a i S JOHN H. MITCHELL,

COMPOSITION PAPER 0R PULP BOARD No Drawing. Application filed March 4,

The invention relates to composition paper or pulp boards and methods of making the same, and has for its principal object the provision of an improved board of this character capable of use for making boxes, barrels, crates, cartons and cylinders, as well as a building material, such as siding, sheathing, roofing, or wall lining, which is capable of production in large quantities, may be made in varying degrees of stillness, thickness, flexibility and strength, and is capable of economical production.

Another object is the provision of an im proved process and method of procedure by means of which a material of this character may be produced by the use of Waste or inexpensive materials, and, therefore, economically.

Other objects-will appear hereinafter I have discoveredithat the comparatively straight and strong fibers from the stems or stalks of certain plants, particularly the bagasse of sugar cane, may be combined, in terlaced and felted with the comparatively crooked and branched fibers and pithy substances from the leaves of fleshy leafed plants, particularly the bagasse ofthe leaves of the sisal or henequen plant, and a strong, durable and efiicient paper, or pulp board produced, of varying stiffness, thickness, flexibility and strength, adapted for various purposes, and at comparatively small cost.

I have learned. that the fibers, particularly the smaller fibers, of the leaves of the sisal or henquen plant, owing to the fleshy nature of said leaves, are provided withamultitude of branching tendrils, branching from all four sides thereof and that these branching tendrils, when said fibers are reduced to a pulp, as in paper making processes, largely retain these branching-tendrils, so that when interlaced and felted with the comparatively straight fibers of the stalks or stems of certain plants, particularly the bagasse of sugar cane plants, the branched tendrils interlock and interlac'e with the other fibers, thereby firmly binding the straight fibers together into a composition paper or pulp board of comparatively great strength and durability.

I have also discovered that the leaf fibers thus produced with branching tendrils have great tenacity, binding eifcct and flexibility, so that by varying t e proportions of the leaf fibers'to the stalk fibers, a board of OFFICE.

OF HABANA, CUBA.

AND METHOD OF MAKING THE SAME.

1927. Serial No. 172,927.

varying stifi'ness, thickness, strength, may be produced commercial requirements.

As indicated above the material produced is, in substance and cl'l'ect, a heavy, stiff, coarse and strong paper and, in general, is produced by subjecting such materials to an adaptation of ordinary paper making processes, especially combined as hereinafter set forth, to produce the desired results.

The process of preparation of the fibrous product or paper making material from the libcrs and pith of comparatively straight and strong stalks, such as sugar cane or the bagasse of sugar cane is the process as specified in U. S. Patent 680,079, granted to George R. Sherwood Aug. 6th, 1901, or U. S. Patent 853,9tl3, granted to Viggo Drewson May 1d, 1907.

III certain other inventions utilizing bagasse and analogous fibers, and cooking the piths and fibers together, the cooking is usually arrested or discontinued at a temperature of 212 degrees Fahrenheit, or under, but I have found that at this low temperature, the lignum, gum and wax compounds are not destroyed, and I prefer to use the flexibility and to meet various higher temperatures under pressure and also 1 use a stronger caustic solution than is usually employed in such processes, such as are disclosed in the said heretofore mentioned patents. The treatment of the materials at the higher temperatures and with a stronger caustic solution will destroy the lignum, gum and wax compounds and thus, besides, freeing the fibers from the pith, destroys the food value of the composition to ants, insects, mice, rats, or the like, and thereby protects the resulting material from attacks by these vermin. Due to the better separation of the bundles of fibers and pith of the plants a product is ultimately obtained of smooth and uniform texture. The products thus prepared are conveyed to a storage and washing tank preparatory to being fed to a mixing tank, as hereinafter described.

Asindicated, one of the purposes of my invention is to destroy, as far as possible, without too much weakening of the product, the lignum and gummy contents of the various fibers or piths, and thereby destroy the attraction for the food value of the completed product for ants, roaches, rats, mice and other vermin. To accomplish this purose the fibers, pithy substances,-juioes of the eaves and stalks of'the fleshy leaved plants after being reduced to propersize ar'efirst cooked in a .60 percent caustic soda solution '.c,ontaining fromt to 12 percent of the-dry J Weight of the-plant -,materials, from 1 to hours and at'a temperature in excess of 212 .degrees'Fahrenheit. As it is intended to use: part of the natural resinous and gummy sub-- .210.

stance as a part of the binding andsizing required to unite the fibers and piths' ingthe completed product, and as it is desired to 'u'se'not less than 15. percent of the original means, to "a storage resin or gummy matters, samples .may .be drawn'oifzfrom time to time to test the cook- -ing process and maintain pIOp61".COI-1l21Ol thereof. After this first cooking is concluded the material is. conveyed by suitable preparatory to being fed to a secondary co'ok- 'er in combination with the waste paper stock. The Waste paper stock havingbeen 'origi-.

nallycookedwill'not require any cooking 'or' treatment except such as to render it sanitary and this can be accomplished by the second" cooking when and, in combination with the fibers and pithy -.substances of the fieshyleavedplants as hereinbefore describedif The waste paper stock having been. reduced torequired size by heaters, grinders or shredders, such as are erally used to a storage. and washing y to' being fed toand' cookedin the secondary .3

'in the second cooking generally usedforthis purpose is conveyed tank preparatory cooker in, combination ,iviththe' fibers and pithy substance "ofthe fleshy leaved' plants as hereinbefore mentioned.

The Waste paper stock, and the pre cooked' fibers. and pith substance from the fleshy leaved plants-havingbeen Washed, and freed.

from the excess of chemicals in cooking liquors, are fed from their respective storage tanks in the various amounts required to a" that generally used and Well known 'in the manufacture of paperandfpulp and the'cooking may be performed by anyof the genable in the open market.

After the stock has been sufficiently cooked process, it is drained to a mixing and cooling tank provided with paddles or agitators with the product or material as prepared uh.-

v der processes specified I as Patents 680,079, or 853,943, mentioned 'aboye,

and -washing tank,

and as applied to,

may be, var ed "palm-tree, cactus and other inthe previous cooking process, andsufs for not paper andpulp cookers purchase and there combined I The" combined products may be water-- .proofed 'or fireproofed by adding, While the stock is being-mixed, any of the ell known and generally'u'sed rosin or aluminum -compounds commercially prepared for the'purpose or purposes, or the product may be used Without such water or fireproofing.

As to the proportions 'of materials used 1 prefer to use about percent of the bagasse of sugar cane, about 20 percent of the bagasse These. proportions may be .of sisal leaves, and about 20 percent' of Waste paper stock. varied considerably depending upon the character of the product desired. The per -centage of waste paperstock may be-c'on- .veniently varied'fr'om 20 to'35 percent by bulk, the more paperst'ockbeing employed the smoother the resultant product "willbe.

Likewise, the proportions of the stalk and lea ffibers may. also be varied,'the more stalk or stem/fibers employed, the stiifer and I stronger andmore rigid will be the product.

Conversely the more of the leaf fibers emplayed the more flexible and lessbrittle Will be the: product. p I also believe that the sources of the fibers the stems .or stalks of plants for the straight and strong fibers andthe leaves stalks or trunks of the banana plant or alm' tree may be employed for the straight fi em,

Within certain limits, usingof fleshy plants for the branching and bln'd ng fibers. lhus, it is thought, that cornsstalks, or' the and the leaves of such plantsas the banana,"

plants havingv heavy andfleshy'leavesmay be, employedfor I providing the branching and tenacious fibers.

The mlxture'of fibers and piths thus provided,'and in the proportions as indicated," depending upon the results desired, 'arereduced to proper-sizes means of shredders,

vdecorticators, grinders, heaters or 'pulver-x izing machines, suchfas are generally used for preparing fibrous materials for pulping in the paper making art, and are of standardmanufactureand purchasable on the openmarket. a

The mixture of fibers is then treated in ordinary paper or pulp making machinery to form the same into sheets or boards of suflicient and pose intended. The processes of pumping, refining, heat ing, felting, pressing,

' or pulp boardthus compressing cutting.- vand dryingof the paper proper thickness for v the purproduced may ,all be efficiently-and inexpensively accomplished by the use ofany of the machines or apparatus marketed forthe manufacture-of paper, paper-board, pulpfiboard, orfiber board. I prefer to 'use for felting purposes one of the manytypes ofimachine known as a wet machine having only one cylinder oras it is also known,.a one cylinder-mould, havin only one foramlnous surface, as this type 0% machine will produce a more homogeneous material than machines having a multiple of foraminous forming surfaces.

The natural interlocking felting and weaving of the material during the felting processes as practiced for many years in the manuta'ct-ure of paper pulp and fiber boards and the compacting or pressing under light or in multiple to gain the desired effect.

While I have set forth and described the preferred composition ,of material and method of producing the same, these are capable of variation and: modification without departing from the spirit of the inven' tion. I, therefore, do not/wish to be confined to the precise details set forth, but desire to avail myself of such variations and 3 modifications as fall within the scope of the appended claims.

I claim: 1. A composition board of the class described consisting of fibers obtained from the stems of sugar cane bagasse bound together by fibers obtained from the bagasse of sisal leaves, substantially as described.

2. The process of preparing a material of the class described consisting in separately cooking the fibers of the stems of plants and the fibers of the fleshy leaves of plants under pressure and at a temperature above 212 degrees Fahrenheit; mixin said leaf fibers with paper stock and cooklng the mixture at a comparatively low temperature and atmospheric pressure; and then-'mixing all said fibers and forming said mixed stock into sheets by paper making processes, substantially as described. a

3. The process of preparing a material of the class described consisting in separately cooking fibers of sugar cane bagasse and fibers of sisal leaves bagasse under pressure and at a temperature above 212 degrees Fahrenheit; mixing said sisal leaf fibers with paper stock and cooking the mixture at a comparatively low pheric pressure; and then mixing all said fibers and forming said stock mixture into sheets by paper making processes, substantially as described.

In witness that I claim the foregoing as my invention I afiix my'signature this 2nd day of March, 1927 JOHN H. MITCHELL.

temperature and atmos- 

